The present invention is directed towards methods of processing semicrystalline, thermoplastic polymers to provide oriented films and to films produced by such methods. In one aspect, an oriented film of semicrystalline, fully imidized thermoplastic polymer is provided.
Oriented polymers have numerous advantages over unoriented polymers in that they possess superior mechanical properties, such as higher strength, improved stiffness, increased toughness and so forth. Semicrystalline thermoplastic polymers have become recognized as attractive candidates for application in the aerospace and electronic industries, because of e.g., their combinations of tailorable properties such as orientation.
Semicrystalline thermoplastic polyimide materials are of a particular interest. However, difficulties in processing such polymers have limited their further application. One class of a semi-crystalline, thermoplastic polyimides developed by NASA Langley Research Center, LARC-CPI, is expected to produce oriented films with mechanical and chemical properties superior to Kapton, Upilix S and other commercially available films. However, film processing techniques that can exploit the thermoplastic and semicrystalline properties of polyimides, such LARC-CPI, and semicrystalline thermoplastic polymers in general are being sought.